On Tuesday, October 11, 2016 at 4:00:20 PM UTC+13, Michael Opitz wrote:
At 22:46 10 October 2016, Martin Gregorie wrote:
On Sat, 01 Oct 2016 00:40:43 +0000, Michael Opitz wrote:

You are welcome. If your Acro doesn't already have the Z tape
installed, I would be interested to hear your opinion as to if the
efficacy of the rudder is noticeably improved (or not) after the
installation. If the fin airfoil profiles of the Twin Astir and the
Acro are close, I suspect that you will notice a favorable
improvement.

I finally checked our Acro II last Sunday: as I thought there's no
fin
turbulation on it, so I've passed your reference to the Lindner TN
to the
relevent club committee member.

It turns out that our Acro now has a fairly low cockpit weight
capacity.
On Sunday we were using it for trial flights but we had to
temporarily
take one of our ASK-21s off scheduled training duties to fly a
reasonably
heavy trial flighter. Some of our members would like to use it for
mutual
XC flying since its a better XC glider than an ASK-21 and has a
decent
SDI flight computer fitted. That said, our ASK-21s do routinely go
XC on
good days with students who are close to soloing - an 80km o/r to
HusBos
is favourite with our paid instructors.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |


Martin,

Low seat load was the reason we sold our Acro several years ago.
If you have a lot of 2 seaters, you can schedule around it, but the
issue becomes a pain if you only have one or two 2-seaters to work
with.

If you can put up with the ground handling issues of a tail dragger,
and a little bit stiffer flight controls, you may find (as we have) that
the original Twin Astir gives a lot for the money invested. A lot of
them had been used as advanced XC trainers, and not for basic
training, so therefore minimal damage history.. This equates to a
retention of the already very high factory seat load of 242 Lbs/seat
plus another 22 Lbs in the baggage compartment. Some even have
water ballast. For XC training, the Twin 1 has a markedly slower
stall speed (with very effective trim) than the Twin II for better
thermalling performance. Best L/D is also ~4 points better than the
Twin II, so it is also noticeably better on the glides as well. For XC
training, I would take the Twin Astir over an Acro any day....IMHO

All you say is correct.

The only problem is the diabolical rear seat shape cause by making room for the wheel to retract.

My club flew a pair of original 1978 Twin Astirs as the basic trainers for about a dozen years (mid 90s to late 00s). They were great in almost every way and a huge step up from the Blanik's we had before them. But the DG1000 18s we've replaced the Grobs result in sooo much less money going to the instructors' chiropractors.